System and method for monitoring heating system

ABSTRACT

A monitoring system is connected to a hot water heating system. The monitoring system includes a controller and various controls and sensors. Sensors are connected to the components of the hot water heating system including the thermostats, pipes, pumps and valves. Controls are connected to the pumps and valves to control operation of the hot water heating system for testing. During normal operation of the hot water heating system, the sensors are monitored to ensure proper operation. If the heating system does not operate within certain defined time parameters, the system is activated to test components of the heating system. An alarm is activated if the system does not operate properly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system and method for monitoring aheating system. More particularly, it relates to a system and method forensuring proper operation of a hot water heating system having multipleheating zones.

2. Discussion of Related Art

Hot water heating systems are commonly used throughout the United Statesand the world. In such system, water is heated by a boiler. The hotwater is distributed through pipes to rooms in a building for heating.Each room to be heated includes a heat transfer device. The heattransfer device may be baseboard heater or a radiator. A baseboardheater is a pipe which extends along the bottom of a wall of the room.The pipe has a plurality of metal fins extending from the pipe. Thestructure includes top and face plates to protect the fins. As hot waterpasses through the pipe, it and the fins are heated. The fins distributethe heat to the air of the room. A radiator is a pipe structure throughwhich the hot water passes. The structure is heated by the water and, inturn, heats the air of the room.

Hot water heating systems are controlled by thermostats. A thermostat inthe room to be heated senses the temperature of the room. When thetemperature drops below a preset level, the thermostat causes the hotwater to pass through the pipes. Typically, the thermostat is connectedelectronically to a pump and valve at the boiler. The valve is openedand the pump is engaged. The valve and pump operate to cause the hotwater to flow through the pipe to the heat transfer device in the room.

Often buildings have multiple heating zones. Each heating zone covers aset of rooms. For each zone, a single pipe extends from the boiler andpasses through the heat transfer devices in each room. A singlethermostat in one of the rooms controls the system for a zone. Each zoneoperates independently. Different zones allow greater control oftemperatures in different rooms. Zone heating allows differenttemperatures to be maintained in different areas of a building. It alsoimproves efficiency and comfort when different areas have different heatloss characteristics.

Hot water heating systems can have a variety of problems which preventproper operation of the system. Thermostats, pumps, valves, pipes andboilers may fail. If a thermostat fails, the system may not turn on toheat the rooms controlled by the thermostat, or may not turn off eventhough the room has reached a desired temperature. If a pump or valvefails, the system may not heat the room or may overheat a room. If pipesfail, water from the system may be discharged into the building. If aboiler fails, the whole heating system will not operate. Failures, inaddition to being an inconvenience, can cause significant damage. If abuilding is not heated properly, water pipes can freeze and burst ormold and mildew may develop. Most damage occurs when the buildingoccupants are not present—in office buildings at night, in homes duringthe day, or when people are on vacation.

Therefore, a need exists for a system to monitor operation of a hotwater heating system. A variety of monitoring systems have been created.However, none of such systems operate to monitor all aspects ofoperation. For example, systems exist to monitor pumps and valves toensure that they are functioning when turned on, but do not determinewhether they are causing hot water to flow. A blockage in the system mayprevent water from moving, even if the devices are operating properly.Furthermore, no systems exist to determine whether the water is properlyreturning to the boiler. Known systems also fail to properly monitormultiple zones to ensure that all zones are functioning properly.

SUMMARY OF THE INVENTION

The present invention relates to a system and method for monitoringoperation of a multi-zone hot water system. The invention includes acontroller connected to a variety of controls and sensors on the hotwater system. According to one aspect of the invention, the thermostatsensors monitor when the thermostats in the system turn on and off.According to another aspect of the invention, flow sensors, connected tothe outgoing pipes from the boiler, determine whether water is flowing.According to another aspect of the invention, temperature sensors,connected to the incoming pipes to the boiler, determine whether hotwater is passing through the entire system. According to another aspectof the invention, controls are connected to the pumps and valves toconduct heating system tests. According to another aspect of theinvention, different operational modes can be selected. Specific sensorsand/or controls may be activated or deactivated based upon theoperational mode.

According to one aspect of the invention, the controller has a basichardware construction. It includes a variety of circuits connected tothe sensors and controls. Each of the circuits controls a test of a zoneof the heating system. The controller includes a display panelindicating operation of the controller. LEDs are lit to indicate whentesting is occurring and the completed status of any tests. Alarms areactivated if a test fails.

According to another aspect of the invention, the controller is operatedin accordance with a method to determine proper operation of the heatingsystem. According to one aspect of the method, maximum and minimum timesare set in the controller. The maximum and minimum times are used todetermine whether the thermostats are turning on properly. According toanother aspect of the invention, a heating system check is periodicallyperformed to test operation of the heating system According to anotheraspect of the invention, the controller is programmable to adjust fordifferent operating parameters. According to another aspect of theinvention, information regarding testing and operation of the system isstored for later review. According to another aspect of the invention,an alarm is activated if the system is not operating properly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a hot water heating system including a monitoringsystem according to an embodiment of the present invention.

FIG. 2 illustrates a display panel for a monitoring system according toan embodiment of the present invention.

FIGS. 3 a-3 c are high level circuit diagrams for a monitoring systemaccording to an embodiment of the present invention.

FIG. 4 is a block diagram of a monitoring system according to a secondembodiment of the present invention.

FIG. 5 is a block flow diagram illustrating operation of a monitoringsystem according to an embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 illustrates a monitoring system 110 for use with a hot waterheating system 100. As is known in the art, the hot water heating system100 includes a boiler 10, a plurality of outgoing pipes 30, 40, 50 and aplurality of incoming pipes 60, 61, 62. The boiler 10 may be of anyknown type which can provide hot water to the heating system. It may usenatural gas, oil, propane, wood, wood pellets, or any other fuel forheating the water for the system. Each outgoing pipe 30, 40, 50 connectsto one or more heat transfer devices (not shown) in rooms to be heatedand to one of the incoming pipes 60, 61, 62. Each of the outgoing andincoming pipes corresponds to a heating zone for the heating system. Athermostat 70, 71, 72 is positioned in a room to be heated within thecorresponding heating zone. The thermostats 70, 71, 72 are connected tothe heating system to control normal operation. A plurality of valves32, 42, 52 are positioned in an outgoing pipe 30, 40, 50 and connectedto a respective thermostat 70, 71, 72. When the thermostat, for examplethermostat 70, turns on, it activates the corresponding valve 32. Hotwater from the boiler 10 passes through the valve 32 and the outgoingpipe 30. It returns on the corresponding incoming pipe 60. A pump 31forces the hot water through the system. A pump 31, 41, 51 is bepositioned on each outgoing pipe and connected to a correspondingthermostat 70, 71, 72. The corresponding pump is activated when thevalve is opened. Alternatively, a single pump can be used for all zonesin the heating system. In such a system, the pump is activated wheneverany of the valves are opened.

FIG. 2 is a display panel 300 to indicate the status of the monitoringsystem and the heating system. Basic operation of the monitoring systemis indicated by the display panel 300. According to an embodiment of theinvention, the display panel 300 is formed as a cover to the controller120 of the monitoring system. Alternatively, the display panel could beseparate from the controller and could be positioned anywhere in thebuilding. The display panel 300 may be wired to the monitoring systemfor direct operation of the panel. Alternatively, the panel andmonitoring system may communicate over a communications link, such as awireless connection, to provide information between the panel and themonitoring system.

The display panel 300 includes various visual and audible indicators anduser actuatable switches. The display panel 300 is labeled to indicatethe purpose and meaning of each of the indicators and switches.According to a preferred embodiment of the invention, the visualindicators are LEDs. However, other types of visual indicators could beused. A first LED 310 indicates when the monitoring system is beingpowered. The system may connect to power for the building it ismonitoring or may have a separate power source. Batteries may be usedeither as a primary or back-up power source for the monitoring system.If the monitoring system is receiving power, then the power LED 310 islit. Two LEDs 311, 312 represent the current operational status of themonitoring system when not in a testing mode. If the standby LED 311 islit, then the system is awaiting a testing period. A testing periodstarts when a thermostat for one of the zones is activated when instandby mode. After a testing period is completed, the monitoring systementers a lockout mode, indicated by LED 312. The lockout mode preventsthe system from conducting another test until a predetermined period oftime has elapsed. After the predetermined time has elapsed, themonitoring system switches from the lockout mode to the standby mode,and turns off LED 312 and on LED 311.

If the monitoring system is in standby mode when a thermostat turns on,a testing period commences for each of the zones in the heating system.The system lights LEDS 321, 322, 323 to indicate that each zone iscurrent in a test mode. As described below, the test mode determinesthat all of the components of the heating system for a respective zoneare functioning properly. Once a test for a zone has been successfullycompeted, the corresponding test LED 321, 322, 323 for that zone isturned off and a completed LED 324, 325, 326 for that zone is turned on.Thus, the panel indicates the current status, either ongoing orcompleted, for each zone.

If a test is not completed properly for any of the zones, one or morealarms are activated. The display panel 300 illustrated in FIG. 2includes four alarms, two visual 331, 322 and two audible 351, 352. Thevisual alarms 331, 332 are LEDs which are lit when an alarm conditionexists. The audible alarms 352, 352 are powered speakers which output asound indicating the alarm condition. Additionally, the system mayinclude other alarm mechanism, such as an autodialer or text messagingdevice to notify an operator at another location of the alarm condition.Two alarms are used to indicate different conditions. One set of visualalarm 332 and audible alarm 351 are used when a problem is detected withthe heating system. The other set of visual alarm 331 and audible alarm352 are used when a power related problem with monitoring system isdetected.

Various switches allow an operator to control the monitoring system. Areset switch 342 is pressed to initialize the system and commenceoperation. The reset switch 342 is also pressed after an alarm conditionoccurs to deactivate all of the alarms and reinitialize the system. Asilence switch 341 is pressed to deactivate the audible alarm 351. Theoperator may want to turn off the audible alarms, since he or she isthen aware of the condition, without restarting the monitoring system,such as during a repair process. A system off switch 344 allows theoperator to deactivate the entire system 110 and silence audible alarm352. An Occupied/Vacation switch is used to indicate a desiredoperational mode. As discussed below, different testing processes may beused when the building is occupied and unoccupied. Some heating systemproblems are readily recognizable by a building occupant, such as aburst pipe. However, the system needs to be able to detect suchconditions and notify the operator, when the building is not occupied.The Occupied/Vacation switch 343 is a toggle switch used to select thedesired operational mode.

FIGS. 3 a-3 c illustrate circuit diagrams for a monitoring systemaccording to a first embodiment of the present invention. FIG. 3 aillustrates the circuitry for the testing system. FIG. 3 b illustratesthe circuitry for controlling the zone valves for testing purposes. FIG.3 c illustrates the alarm tie in for the security system or auto-dialer.The circuitry of the monitoring system include various relays whichprovide the necessary delays, light the LEDs and activate alarms.

As illustrated in FIG. 3 a, the circuitry of the monitoring system isconnected to a voltage source 410, such as a low voltage transformer. Asdiscussed above, power may be provided by a connection to building poweror to a battery. The reset switch 342 operates to disconnect andreconnect the power source 410 in order to initialize the monitoringsystem. Then power is supplied to the system, LED 310 is lit. An alarmcircuit 420 operates to control the alarms. As discussed above, thesystem alarm and boiler alarm are handle separately. The circuitry forthe system alarm 440 is illustrated in FIG. 3 b. The circuitry for theboiler alarm 420 is part of the test circuit illustrated in FIG. 3 a.The silence switch 341 is used to activate/deactivate the audible alarm351 using an audible alarm circuit 422. A time delay relay 412 is usedin the standby circuit 430 to control the lockout/standby condition. Thetime delay relay 412 is used to prevent overtesting of the system, evenwhen the thermostats may be turning on and off frequently. According toan embodiment of the invention, the time delay relay 412 is designed toprovide a 60 minute delay. Of course, a longer or shorter time could beused. Also, the time may be adjustable.

Upon initialization or resetting of the system, the unit is in standbymode and LED 311 is lit. The system then awaits activation of one of thethermostats in the heating system. The thermostat inputs are illustratedin FIG. 3 b. If either of the three thermostats activates, then relay 2of the circuit of FIG. 3 b activates the testing system. When activated,the system turns on the zone valves for all of the zones, using thecircuitry illustrated in FIG. 3 b. The power circuit 441 provides powerto the transformer for the circulating pump. In the embodimentillustrated in FIGS. 3 a-3 c, the heating system includes a singlecirculating pump. Of course, as discussed above, the heating system mayinclude multiple circulating pumps. With such a system, additionalcircuitry would be used to activate each of the respective circulatingpumps. When the test is activated, the zone control valves 32, 42, 52are turned on using zone control circuits 442, 443, 444. The system alsoactivates the test mode circuitry through relay 2 in the start testcircuit 445.

During the test mode, a second time delay relay 411 is used to control amaximum time for the test mode. According to an embodiment of theinvention, a maximum test period of 15 minutes is used. Of course, othertime periods could be used. Also, the test period could also bedependent upon the occupied/vacation mode switch since the time fortesting under vacation mode will likely be longer than for occupiedmode. When in test mode, each of the test LEDs 321, 322, 323 are lit bythe test circuits 424, 425, 426.

In order to successfully complete a test mode for each zone, an outputfrom a thermal sensor on the zone must be received. Thermal sensors areconnected to each of the output and input pipes for the heating system.Under occupied mode, the thermal sensors on the output pipes are used.For vacation mode, the thermal sensors on the input pipes are used.Using the output pipes during an occupied state allows the test to beconcluded more quickly, since the output side pipe will begin heating assoon as hot water is flowing. However, in vacation mode, the systemneeds to ensure that heat is getting to the entire zone, not justleaving the boiler. Therefore, the input pipes are used for determiningthat the entire heating system has been traversed. Switch 343 controlswhich set of thermal sensors are used. The thermal sensors are set at apredetermined temperature level, such as 130 degrees. When that level isreached, the sensor triggers a respective relay which turns off the testLED and turns on the test completed LED. The circuitry also turns offthe respective zone control valve, unless it is still being operated bythe thermostat.

Once all of the zones have completed the test mode, the system resets tolockout mode. However, if any of the zones has not completed testingwhen the time delay relay 411 closes, the alarms are activated.

FIG. 3 c further illustrates an alarm tie-in circuitry. If power is lostor the system detects a problem with the boiler, the system can notifyan operator or the condition. The notification can be provided to asecurity company. The security company may monitor other conditions forthe building, such as break-ins and fire. Alternatively, the securitycompany may just monitor the heating system. The tie-in may also connectto an auto-dailer for calling the owner or manager when certain problemsoccur. Any phone number or multiple phone numbers may be called by theautodialer. The system can also provide different types of conditionsfor activating the alarm tie-in. For example, the system may delay thealarm notification for a predetermined period of time for a poweroutage, but may activate the alarm notification immediately when aboiler problem is detected.

FIG. 4 illustrates the components of a monitoring system 110 accordingto a second embodiment of the present invention. In this embodiment, themonitoring system includes a programmed processor instead of thehardware circuitry of the first embodiment. The core of the monitoringsystem 110 is a controller 120. The controller 120 is preferably aprogrammed processor having a variety of inputs and outputs. Anappropriately programmed general purpose computer could be used as thecontroller. Similarly, a hardware-based processing device can be used.The controller 120 may use analog or digital inputs and outputsdepending upon the nature of the hot water heating system to which it isconnected.

The inputs to the controller 120 include various sensors 150, 160, 170which are connected to the hot water heating system. Generally, eachtype of sensor is connected to components for one of the zones of theheating system. For example, as illustrated in FIG. 1, a set of flowsensors 150 include one flow sensor 151, 152, 153 connected to acorresponding outgoing pipe 30, 40, 50. A flow sensor 150 determineswhether water is flowing in the pipe to which it is connected. Any typeof known flow sensor 150 can be used with the monitoring system 110 ofthe present invention. Alternatively, as discussed below with respect tooperation of the monitoring system, temperature sensors could be used inplace of flow sensors. Temperature sensors 160 are connected to theincoming pipes 60, 61, 62, to determine the temperature of the pipes.Thermostat sensors 170 are connected to the electronic outputs of thethermostats to determine whether the thermostat is on or off.

The controller 120 includes various control outputs for controllingcomponents of the heating system. As with the sensors, each control isconnected to a corresponding one of the components for a heating zone.Pump controls 130 are connected to a corresponding pump 31, 41, 51 tostart or stop operation of the pump. Of course, if the heating systemuses a single pump for all heating zones, then a single pump control 130would be used. Similarly, valve controls 140 are connected tocorresponding valves 32, 42, 52.

The monitoring system 110 includes a memory 180 connected to thecontroller 120. Information determined by the monitoring system isrecorded in the memory 180. Such information may include times duringwhich zones of the heating system were operating, times for heatingsystem tests, and results of tests.

The monitoring system 110 also includes an alarm 180. The alarm 180 isused to notify an operator when the heating system is not functioningproperly. The alarm 180 is connected to the controller 120. When thecontroller 120 determines that the heating system has a problem, thealarm 180 is activated. The alarm 180 may be of many known types and mayinclude multiple types. For example, the alarm 180 may include a sirenand/or light which are activated to provide an audio and/or visualindication of a problem. The siren and/or light may be located near theheating system, elsewhere within the building being heated, or at adistant location. Alternatively, the alarm 180 may include a messagedevice for providing a message to an operator. The message device dial aprogrammed telephone number and play a message. It may send and email ortext message to a programmed address. It may activate a pager. If thealarm 180 includes multiple types, it may activate different onesdepending upon the nature of the problem determined by the monitoringsystem.

FIG. 3 illustrates the monitoring operation 200 of the system accordingto an embodiment of the present invention. The monitoring operation 200is a loop programmed into the controller 120. Once activated, the loopstarts at step 210. The first step 210 determines whether a thermostatis turned on. As noted above, each of the thermostats are monitored.Depending upon desired operation, step 210 may determine whether any ofthe thermostats are turned on or whether only a particular one is turnedon. Since the thermostats operate on independent schedules, one could beturned on at all times. Thus, according to an embodiment of theinvention, only one thermostat is used to control operation of themonitoring system. However, all of the thermostats are monitored. Thetimes during which the thermostats operate may be recorded in thememory. Also, the monitoring system may determine whether any thermostatis turned on for too long a time or left off for too long of a time.Such monitoring is easily included within the monitoring system of thepresent invention, but not part of the general monitoring processillustrated in FIG. 3.

When a thermostat turns on, the process moves to step 220. At step 220,the system determines whether a minimum time as elapsed since the lastsystem test. The thermostat may turn on and off frequently. A fullsystem test may not be required as frequently. Therefore, a minimum timeis set for the system test. If the minimum time has not been met, theprocess continues at step 230. At step 230, the sensors for the zonewhich is on are monitored. At step 270, the process determines whetherthe monitored sensors are within specified ranges. Monitoring of sensorsand determination of problems are discussed below with respect to thesystem test.

If a thermostat is not turned on, as determined at step 210, the processdetermines, at step 240, whether a maximum time has been reached sincethe last system test. Ambient conditions may prevent a thermostat fromturning on. Also, the thermostat may have failed. The system shouldstill be tested periodically, such as every hour or every day. Thus,even if the thermostat is not turned on, the system will conduct a testwhen the maximum set time is reached. Of course, the system could betested in accordance with preset times. However, such operation would beinefficient. The heating system must be operated during the testingprocess and operating the heating system requires energy. The process asillustrated in FIG. 3 allows testing when the heating system is alreadyoperating, but also controls the process to prevent the too frequent orinfrequent testing of the heating system.

A full heating system test occurs at step 250. A heating system testresults when the selected thermostat turns on after the minimum time aselapsed (from step 220) or when the maximum time has elapsed (from step240). For a full system test, all of the heating systems are turned on.The valve controls 140 and pump controls 130 are activated. Under normaloperation, activation of the controls will cause hot water to passthrough all zones of the heating system. The controls are activated onlylong enough to test the system. Then, they are deactivated. Of course,if any of the thermostats are on when the controls are deactivated, thepump and valve for that zone will remain on for normal operation of theheating system.

While the system is activated, the sensors are monitored (step 260) todetermine (step 270) whether the system is operating properly.Specifically, the flow sensors 150 and temperature sensors 160 are usedto determine proper operation. First, the flow sensors 150 are checkedto determine whether water is flowing through the outgoing pipes. Ifwater is not flowing through any of the pipes, the problem is recordedin the memory 180 and the alarm 170 is activated. After a predeterminedperiod of time, the temperature sensors 160 are checked. The temperaturesensors provide the temperature of the incoming pipes. If water isproperly flowing, hot water will pass completely through each zone fromthe outgoing pipe to the incoming pipe during the predetermined periodof time. The hot water returning in the incoming pipe will heat thepipe. Thus, the temperature sensor can be used to determine whether hotwater is flowing in the pipe. If the temperature of the pipe is notabove a threshold after the predetermined time, then hot water is notflowing entirely through the system. The problem is recorded in thememory and an alarm is activated. Temperature sensors could be usedinstead of the flow sensors for the outgoing pipes. If water is flowingin the pipes, the outgoing pipe will also get hot from the flowingwater. The period of time and temperature threshold for the outgoingpipe would be different than those values for the incoming pipe toaccount for the differences in location and water temperature within theheating system.

Having disclosed at least one embodiment of the present invention,various adaptations, modifications, additions, and improvements will bereadily apparent to those of ordinary skill in the art. Suchadaptations, modifications, additions and improvements are consideredpart of the invention which is only limited by the several claimsattached hereto.

1. A method for monitoring a hot water heating system for a building,the heating system having at least one thermostat for controlling theflow of hot water through pipes from a boiler to a heating zone of thebuilding, the method comprising the steps of: determining when the atleast one thermostat is activated; determining whether hot water isflowing in the pipes of the heating system when the at least onthermostat is activated; and activating an alarm after determining thathot water is not flowing in the pipes.
 2. The method for monitoring ahot water heating system according to claim 1, wherein the step ofdetermining whether hot water is flowing includes the step ofdetermining a temperature of pipe of the heating system.
 3. The methodfor monitoring hot water heating system according to claim 2, whereinthe temperature of the pipe is determined at an output from the boiler.4. The method for monitoring hot water heating system according to claim2, wherein the temperature of the pipe is determined at a return to theboiler.
 5. The method for monitoring hot water heating system accordingto claim 2, wherein the temperature of the pipe is determined at alocation which depends upon a operational parameter of the heatingsystem.
 6. The method for monitoring hot water heating system accordingto claim 2, wherein the step of determining whether hot water is flowingincludes the step of determining whether the temperature of the pipeexceeds a threshold temperature within a predetermined time.
 7. Themethod for monitoring hot water heating system according to claim 1,wherein the alarm includes a visual indicator.
 8. The method formonitoring hot water heating system according to claim 1, wherein thealarm includes an audio output.
 9. The method for monitoring hot waterheating system according to claim 1, wherein the alarm includes acommunication device for providing a notification of the alarm to aremote location.
 10. The method for monitoring hot water heating systemaccording to claim 1, the heating system having a plurality ofthermostats for controlling the flow of hot water through pipes from aboiler to a plurality of respective heating zones of the building,wherein the step of determining when at least one thermostat isactivated includes the step of determining when any of the plurality ofthermostats are activated, the method further comprising the steps of:opening all pipes from the boiler when any of the plurality ofthermostats are activated; and closing each pipe corresponding to athermostat which is not activated when hot water is determined to beflowing in such pipe; and wherein the step of activating an alarmincludes activating an alarm if hot water is not flowing in any pipe ofthe heating system.
 11. The method for monitoring hot water heatingsystem according to claim 10, further comprising the step of determininga time period since all pipes were opened, and wherein the step ofopening all pipes occurs only when the time period exceeds apredetermined time period.
 12. The method for monitoring hot waterheating system according to claim 10, further comprising the steps of:determining a time period since all pipes were opened; and closing eachpipe when the time period exceeds a predetermined time period.
 13. Asystem for monitoring a hot water heating system for a building, theheating system having at least one thermostat for controlling the flowof hot water through pipes from a boiler to a heating zone of thebuilding, the system comprising: at least one temperature sensorattached to at least one of the pipes; a circuit for determining whenthe at least one thermostat is activated; a time delay circuit fordetermining whether the at least one temperature sensor registers atemperature above a threshold within a predetermined time after the atleast one thermostat is activated; and an alarm circuit providing analarm when the temperature sensor does not reach the threshold withinthe predetermined time.
 14. The system for monitoring hot water heatingsystem according to claim 13, wherein the at least one temperaturesensor is positioned on an output pipe from the boiler.
 15. The systemfor monitoring hot water heating system according to claim 13, whereinthe at least one temperature sensor is positioned on a return pipe tothe boiler.
 16. The system for monitoring hot water heating systemaccording to claim 13, wherein the at least one temperature sensorincludes at least one first temperature sensor positioned on an outputpipe from the boiler and at least one second temperature sensorpositioned on a return pipe to the boiler, the system furthercomprising: an input for selecting one an output of the firsttemperature sensor and the second temperature sensor to be used inconnection with the time delay circuit.
 17. The system for monitoringhot water heating system according to claim 13, wherein the alarmcircuit includes a speaker to provide an audio output.
 18. The systemfor monitoring hot water heating system according to claim 13, whereinthe alarm circuit includes an output for providing a notification of thealarm to a remote location.
 19. The system for monitoring hot waterheating system according to claim 13, further comprising a displayproviding a visual indication of operation of the system.
 20. The systemfor monitoring hot water heating system according to claim 13, theheating system having a plurality of thermostats for controlling theflow of hot water through pipes from a boiler to a plurality ofrespective heating zones of the building, the system further comprising:at least one relay for controlling opening and closing of pipes; a relaycontrol circuit connected to the at least one relay for opening allpipes from the boiler when any of the plurality of thermostats areactivated, and closing each pipe corresponding to a thermostat which isnot activated when the temperature when a corresponding one of the atleast one temperature sensors reaches a predetermined threshold.
 21. Thesystem for monitoring hot water heating system according to claim 20further comprising: a second time delay circuit for preventing operationof the at least one relay before a predetermined time all pipes werepreviously opened.